Ball valve

Dippypud

I did mine last year on the Cold water tank and 3 months before that for the CH header.

Took my time, turned the water off etc. not bad for a 52 yr old bird.:cool:

Mind you, last week I recarpeted the downstairs cloakroom, and took the WC out to do that properly.:D:cool:

Plumberman

If the CWT is only overflowing when the HW is on it may be that the ball valve just needs adjusting. Water expands when it gets hot and raises the water level in the tank. If the ball valve needs rewashering or renewing, the CWT will overflow regardless of the HW being on. This will be most noticeable when HW has not been drawn off for a while, probably first thing in a morning or if you have been out all day.

I personally cannot understand why any respecatable plumber would not carry a ball valve (or BV washer) in his van.
I have at least 3 ball valves, a couple of torbecks, a few float valve and dozens of washers in my van.